Casing perforating and screen plug setting device



Filed lay 27, 1968 H. A.'TAGGART CASING PERFORAAIING AND SCREEN PLUGSETTING DEVICE 4 Sheets-Sheet 2 26 i. l ss ,2e

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PERFORATING -AND SCREEN PLUG SETTING DIEIVIGE.A

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vmvmrToR Filed Au@ 19,1959 L AJM-:GAM l y* 43.461,97?

' CASI TI'NG AND SCREEN PLU SETTING 'DEVIGE v 4 Sheetsi-Sheet 4* l FIG.12 1 A y u NTO INVE. R'

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' L ABSTRACT or THE mscLosURE IThe invention relates to a device whichAwill selectively perforate a well casing, and at the same time insert afilter plug in the perforation which will be held fast, and

prevent sand and other unconsolidated materials from entering thecasing.

In` current well completion practice, a steel casing is lowered in thehole and 'cemented into place. The cement is forced down vthe casing andup between the casing and the |bore hole. In doing this the formation iscompletely shut offfrom the casing, and in order to produce the uids'from the formation, the casing and cement must be perforated. The usualpractice is to set the casing in cement as described above and thenselectively perforate "the casing and cement opposite oil or gas sands.This prevents the production of water, since the Water sands are leftshut oi behind the cement.

Many times the producing sands are unconsolidated vand flow into thewell with the fluids being produced 'and cause sanding up in the well,and damage to the equipment. When this occurs the production equipmentinust be pulled and the well cleaned out. Many different `approacheshave been taken to solve the problem of sand production. The approachtaken here is to plug the perforation with a fluid permeable filterplug, and

thus prevent the sand from entering the well bore. The

procedure of selectively perforating cemented casing precludes thepossibility of placing lters or screen plugs `in the casing before thecasing is set in the' well, because theV cement must also be perforatedafter it has set up in the hole.

" 'The device disclosed herein is by necessity designed to operate inthe limited space of the casing, and therefore the utilization ofavailable space becomes an impor'tant'factor. The design must also takeinto account fhydrostatic pressures of the drilling fluid in the xwellbore. With these factors in mind, an object of the present invention isto present a Well casing perforating and screen plug setting devicewhich is'compact in design, 'and which will perform the functionsetforth in fthyis specification under relatively great hydrostaticpres- Slll'eS.

y .Another object is to provide a perforating and screen plug settingdevice which may be lowered into a well and perform' the above mentionedfunctions after the casingjhas been lowered and cementedinto place.

j Another object of the invention is to provide a device which willpermit standard well completion and water fshut off practices, and atthe same time eliminate theneed United Sme Pff for setting screens,gravel packs and the like. The screen A setting process will instead becombined with theusual Vof the invention is tol create a and at' anyselected point, be locked in position in the casing by electric meansfrom the surface. lAlso upon command from the surface the' casing may beperforated `and theA screen plug set in the perforation. Subsequent e3,461,977; Patented Aug. 19, 19,69

to thislthe device may be freed from its position in the casing andretrieved from the well.I

A further object is to offer an oilwell casing perforating and screenplug setting device which contains multiple units as described above andwhich willperform the perforating and screen plug setting operation' at`selected ICC ,points in the casing a number of times withoutnecessitating the removal of the device from the Well bore.

Yet, another object of this invention is to provide a casing perforatingand screen plug setting device with the versatility described and yetrelatively simple in design, freel from operating failure andinexpensive to fabricate. l

The novel features and functions of the present invention can best beunderstood by reference to the followingspecification in conjunctionwith the accompanying drawinginwhich:

FIG. 1 is a longitudinal cross-section view of the casing perforatingand screen plug setting device in free suspension in the well casing.

FIG. Z is also a view in longitudinal cross-section, but locked in rigidposition in the well casing.

FIG. 3 is a top view of the device showing an individual tiring cylinderand part of its electrical apparatus.

FIG. 4 is a longitudinal cross-section view of an individual firingcylinder taken along line 4-4 of FIG. 3.

FIG. 5 shows an exploded view of an individual firing cylinder, itsplacement in the main housing and its spring and retaining ring.

FIG. 6 is an illustration of a iilter plug with helical fins after ithas been fired into the casing perforation.

FIG. 7 shows .the forward end of a filter plug.

FIG. 8 is a longitudinal section view of a filter plug showing thefiltering granules and screens.

FIG. 9 is a longitudinal cross-section of one of the hydraulicpositioning jacks holding the device rigid in the wellcasing.

FIGS. 10 and 11 are cross-sectional views of a firing cylinder takenalong line 10-10 of FIG. 3. FIG. 10 shows the position of the tiringcylinder before firing. FIG. 11 shows the position of the firingcylinder after the perforating bullet has been red, the tiring cylinderrotated and the lter plug fired into the casing perforation.

FIG. 12 is a top view of the cylinder position shown in FIG. 11, showingthat the terminals in this position are in electrical contact. l

Referring now to the drawings, FIG. 1 shows a cross section view of thedevice suspended in the Well casing 13 on the electrical conductor-corecable 12. The casing traverses the earth formation 14, and has been setin the cement 15. It can be seen at this point that the formation 14 iscompletely shut olf by the cement 15 and the casing 13. l

The positioning jacks 16 are hydraulically operated and are used toforcethe device against the casing and hold it rigid while theperforating and plugging operation takes place (FIGURE 2). When themotor 17 is started, the threaded shaft 18 begins to unscrew from itsmatching threaded member'19 and causes the piston 20 to expel thehydraulic uid from the chamber 21 and into the hydraulic system whichactivates the positioning jacks. The pressure sensitive switch 22 shutsoff the motor when a suicient pressure is built up in the system to holdthe device rigid in the casing. After the perforating and pluggingoperation the motor is reversed, drawing the fluid back into the chamber21 and retracting the jacks 16. FIGURE 2 shows the device after it hasbeen positioned by the jacks. 'Ihe switch 23 shuts off the motor whenthe threaded member 19 is brought down in contact with it, as in FIGURE1 The firing cylinders 24 have two chambers; one fires a bullet whichperforates the casing and the other fires a filter or screen plug intothe perforation (see FIGURES 4 and 5 The firing cylinder rotates withinthe main housing 25. After the perforating bullet has been fired throughthe casing, the filter plug chamber is rotated into alignment with theperforation and the filter plug is then fired into the perforation.

FIGURE 3 is a top detail view of a firing cylinder, and FIGURE 4 is asection view taken along line 4--4 of FIGURE 3. The hydraulic line 26carries fluid to the positioning jacks 16. The wire 27 runs fromcylinder to cylinder for the electrical firing of the perforatingbullets. In FIG. 4 the terminal 28 makes contact with the firing element29 which employs a Nichrome wire 30 in contact with the gun powder 31,and grounded to the device to complete the circuit. When a current ispassed through it, the Nichrome wire 30 burns, and ignites the powder31. When the bullet 32 is fired the explosive pressure drives the pin 33back, which in turn drives back the spring loaded catch 34 and releasesthe firing cylinder. The firing cylinder is under spring tension byvirtue of the spring 35. The spring 35 is held on the firingcylindershaft 36 by the snap ring 37 (see FIGURE 5). As the bullet 32 is firedthrough the bullet firing chamber 38 and the catch is released, thefiring cylinder spins 180, aligning the filter plug chamber 39 with theperforation made by the bullet. FIGURE shows the position of the firingcylinder 24 before the bullet is fired. FIGURE ll shows the firingcylinder 24 after the bullet 32 has been fired and the cylinder has spun180. The spring loaded member 40 drops into the slot 41 in the firingchamber 24 and fires the primer cap 42 and ignites the powder charge 43which drives the filter plug 44 into the perforation. FIGURE 4 shows thepacking 60 which serves as a gas seal and pushes the filter plug 44ahead of it as the charge 43 explodes.

FIGURE 6 is a detail of the filter plug 44 after it has been driven intothe casing 13. The helical fins 45 are made of hardened steel and causethe plug to spin through the casing 13. As the fins cut through theother side of the casing 13, they spin out of the grooves 46 which theyhave cut, and thereby lock the plug in place. It should be noted in theenclV view of the plug (FIGURE 7) that the fins 45 are not spaced atequal angles from each other, so the plug cannot come out unless it hasturned exactly 360, exactly the way it has entered. FIGURE 8 is alongitudinal section view of the filter plug. The screens 47 enclose thefiltering granules 48. The screens are held in place by the retainerplates 49a and 49b. The shoulder 50 holds the rearward retainer plate49a in place While the snap ring 51 holds in the forward retainer plate49b.

FIGURE 9 is a detail section of one of the positioning jacks 16. This isa simple telescoping hydraulic jack. It has been activated by fluid fromthe lines 26 and has forced the main housing 25 against the well casing13. The jack 16 is held in the main housing 25 by the snap ring 52.

The explanation of the wiring system is as follows: FIGURE 3 shows theelectrical terminal 28 connected to the incoming wire 27a and it, inturn, is resting on the firing element 29 which is seen in FIGURE 4. Theother terminal 53 in FIGURE 3 is connected to wire 27b and is resting ona strip of insulating material 54. Both terminals are mounted on theinsulator 55, so a broken connection exists between the two terminals.FIGURE l2 shows the two terminals resting on a conducting material 56after the firing cylinder has fired and rotated 180 as in FIGURE 11. Thewires 27a and 27b are now in electrical contact and wire 27b leads tothe next firing cylinder, making it ready for firing. This can berepeated for any number of cylinders.

FIGURES 4 and 6 show the placement of the gasket 57 on the filter plug.The gasket 58 in FIGURE 4 seals the device and prevents leakage of wellfluids into the electrical conductor-core cable containing two wires forthe hydraulic system motor and one wire for firing the perforatingbullets. When the desired point is reached for perforating, thepositioning jacks are activated and the device is forced against thecasing with the firing chamber muzzles `against the casing. The firingelement is then activated. The perforating bullet is fired through thecasing, the catch is released and the firing cylinder spins around to apoint aligning the filter plug chamber with the perforation. At thispoint the primer cap is fired, driving the filter plug in theperforation. Thefiring cylinder in this position has left the nextfiring cylinder in electrical contact and ready for firing. After theoperation is completed the hydraulic system motor is reversed, the jacksretracted and the device retrieved from the well, or moved to the nextselected interval to be perforated.

Although I have illustrated and described a specific embodiment of myinvention it should be understood that many substitutions andmodifications may be made with'- out departing from the true spirit ofthe invention.

What I claim is:

1. A casing perforating and screen plug setting device for oil wells andthe like consisting of a tubular housing suspended in a well casing onan electrical conductor-core cable; said tubular housing containing aplurality of cylinders, the longitudinal axis of said cylinders disposedtlasversely to the longitudinal axis of said tubular housing; saidcylinders rotatable relative to said tubular housing with spring meansurging said rotation; a releasable catch between said cylinders and saidtubular housing to prevent relative rotation, said cylinders having twodiametrically opposed chambers along said cylinders longitudinal axis,one chamber vhaving a charge driven projectile suitable for perforatinga steel casing; the other chamber having a charge driven filter plugequipped with helical fins suitable for holding fast when driven into acasing perforation; said tubular housing equipped with hydraulic jackswhich may be activated to force said tubular housing against said casingand hold said tubular housing stationary within said casing; saidcomponent parts being so arranged that the tubular housing may belowered into the larger tubular casing and locked in rigid position insaid casing, said projectile may then be fired through the casing byelectric means through the electrical conductor-core cable; said catchmay then be released, allowing the cylinder to rotate to a pointaligning the filter plug with the perforation made by the projectile,said filter plug may then be red into said perforation; said jacks maythen be retracted and said tubular housing retrieved from said casing.

2. The casing perforating and screen plug setting device of claim 1wherein said cylinders are equipped with circular gaskets to preventdrilling fiuids from enten ing said tubular housing.

3'. A casing perforating and filter plug setting device for oil wellsand the like consisting of a tubul-ar housing suspended in a well casingon a line from the surface; said tubular housing containing a pluralityof cylinders, the longitudinal axis of said cylinders disposedtransversly to the longitudinal axis of said tubular housing; saidcylinders being rotatable relative to said tubular housing with springmeans urging said rotation; a releasable catch between said cylindersand said tubular housing to prevent relative rotation, said lcylindershaving two chambers along said cylinders longitudinal axis, one chamberhaving a projectile and means for driving said projectile through asteel casing; the other chamber having a filter plug and means fordriving said filter plug into a casing perforation; said tubular housingequipped with clutches which may be activated to hold said tubularhousing stationary within said well casing; said component parts beingso arranged that the tubular housing may be lowered into the well casingand locked in rigid position in the casing, the projectile may then bedriven through the casing on command from the surface, said catch maythen be released, allowing the cylinder to rotate to a point aligningthe iilter plug with the perforation made by the projectile, said lilterplug may then be driven into said perforation; said clutches m-ay thenbe retracted and the tubular housing retrieved from the well casing.

4. A casing perforating and screen plug setting device as describedcomprising; a tubular member suspended in a well casing on -a cable fromabove; said tubular member having a plurality of rotatable cylindersdisposed transversly to the longitudinal axis of said tubular member;spring tension urging said cylinders to rotate relative to said tubularmember, a releasable catch between said tubular member and saidrotatable cylinders preventing relative motion therebetween; each ofsaid cylinders having two chambers, one of which chambers employs aprojectile and means of propelling said projectile through said wellcasing; the other chamber employs a filter plug 20 and means of drivingsaid filter plug into a perforation in said casing: said device equippedwith clutches which 6 may be activated to hold said device stationary insaid casing: said parts being so arranged that the clutching process aswell as the perforating and plugging operations may be activated fromthe upper end of said cable.

References Cited UNITED STATES PATENTS 2,210,983 8/1940I MacClatchie175-4.5 2,426,517 8/1947 McWhorter 175-4.5 2,482,913 9/1949 Jobe166-55.1 2,559,687 7/1951 Thomas 166--55.1 X 2,587,723 3/ 1952 Githenset `al 175-4.5 2,614,633 10/1952 Broyles a 166-55.1 3,245,472 4/1966Zandmer 166-100 3,318,393 5/1967 Brown 166--100 X DAVID H. BROWN,Primary Examiner U.S. Cl. X.R.

